1. Field of the Invention
This invention relates to a component pressing device which presses a component to a substrate using a voice coil motor.
2. Related Art
A component mounting apparatus for mount an electronic component to a substrate by pressing is provided with a load generating means for generating pressing load to press the electronic component to the substrate. There is known one conventional load generating means constituted by using a voice coil motor that is provided with a combination of coils and magnets. In this construction, a thrust force, which is generated by energizing the coils in magnet fields provided by the magnets, is transmitted to the electric component through an electronic component holding tool (see, for example, JP-A-2003-319632). In JP-A-2003-319632, two magnets having different directions of magnetization are arranged in series along a thrust generation direction, and two of inner and outer layers of coils are provided to sandwich the magnets, so that high thrust force is obtained.
In recent years, accompanying with diversification in variety of electronic components, there have been required component pressing devices which can apply high mounting loads, for mounting large-size chips such as CCD and CMOS components etc. One option to realize mounting operations with the high mounting load would be to increase the thrust force of the voice coil motor itself. However, for this option, it is necessary to provide magnets larger than the magnets conventionally used. However, such the large magnets have problems in availability in the market, and it is difficult to obtain large magnets that satisfy required specifications under reasonable costs and desired delivery deadlines. Further, it is not avoidable that the size and weight of the voice coil motor are increased as a result of obtaining high thrust force. That is against demands to make the mounting, apparatuses compact. As discussed above, there have been problems in the conventional component mounting apparatus in adapting high mounting loads due to limitation of the thrust force of the voice coil motor.